巻号一覧
56 巻, 2 号
選択された号の論文の11件中1～11を表示しています
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研究論文
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中森 秀樹, 時末 光, 嘉賀 健太, 平塚 傑工2006 年 56 巻 2 号 p. 77-81
発行日: 2006年
公開日: 2006/06/16
ジャーナル フリーDiamond-like carbon (DLC) films have been deposited on various aluminum alloys by ion plating method. Prior to DLC deposition, various interlayers were deposited on the alloys using several deposition methods. Tribological properties of such coated materials were measured using the ball-on-disk characterization method. Aluminum alloys improved by DLC films was friction coefficient of about 0.2 to 0.3. It was also found that the nature of the interlayer has an influence on the wear properties of the DLC film. It was also found out that the best interlayer is different for each type of aluminum alloy. Between the tested combinations of interlayers/aluminum alloys, 6061 alloy with a SiC interlayer showed the most excellent wear properties.抄録全体を表示PDF形式でダウンロード (888K) -
石井 勝也, 尾崎 良太, 金子 賢治, 増田 正孝2006 年 56 巻 2 号 p. 82-87
発行日: 2006年
公開日: 2006/06/16
ジャーナル フリーThe Amount of aluminum corrosion was critically measured in deoxidized pure water. It was indirectly calculated from the pressure of the hydrogen gas produced by the cathodic reaction. The accuracy of this device reached as high as 0.1 mg/m2. The corrosion rate of A1N99 (99.99% aluminum) was then examined and compared with the images taken by both scanning electron microscope (SEM) and transmission electron microscope (TEM). In particular, images of the surface were taken by SEM and that of the cross section by TEM. From these comparisons, a new corrosion mechanism was proposed; 1) aluminum corrosion starts by the formation of small pits with a diameter of about 0.1 μm, 2) the number of these small pits increases and spreads over the entire surface. In addition, there is a time-lag between the increase of hydrogen gas pressure and the formation of corrosion products on the surface. The most likely reason for this time lag is that the Al ions require a long period of time to form stable oxide films.抄録全体を表示PDF形式でダウンロード (1312K) -
阿部 晴彦, 小松 伸也, 浜岡 真人, 池田 勝彦, 桜井 健夫2006 年 56 巻 2 号 p. 88-93
発行日: 2006年
公開日: 2006/06/16
ジャーナル フリーFixing the room temperature pre-aging for 86.4 ks (RTP) and the temperature of isothermal final aging at 448 K, double aging behavior of Al-1.0%Mg2Si-0∼0.72%Cu alloys was investigated by resistometry and tensile test. Specimens were water quenched after solution treatment at 848 K for 3.6 ks (STQ), aged, measured resistivity at 77 K (ρD77) and then tensile tested. The Cu addition suppressed ρD77 increment by room temperature aging until about 20 ks, whereas in later stage Cu enhanced the increment. After the RTP, proof stress (σ0.2) increased slightly with Cu addition. Similarly as previously reported 473 K aging, the Cu addition accelerated hardening by single 448 K aging after the STQ, enhanced the ρD77 increment in early stage and lowered the ρD77 decrement in peak hardening (448 K-259 ks) state. Though in the base (no Cu) alloy the RTP gave a larger σ0.2 in an assumed bake hardening (B.H.: 448 K-1.2 ks) state of car body, the RTP lowered the B.H. of Cu added alloys. 448 K isothermal age-hardening of no RTP specimens exceeded that after the RTP. The aging time corresponding to cross point of age-hardening curves of no and with the RTP specimens became shorter with Cu addition than the assumed B.H. time, 1.2 ks. However, on the peak hardening state by the final aging, the RTP had no effect, and σ0.2 of both specimens nearly coincided with each together. Until peak hardening, i.e. during the period in which σ0.2 of the no RTP specimens exceeded that of the specimens with RTP, ρD77 of the latter was higher than the former. It is evident from these observations that a part of the RTP products, clusters or zones, or some precipitates changed from them at 448 K, survive until the peak hardening state and result the negative effect of pre-aging famous in 6000 series alloys.抄録全体を表示PDF形式でダウンロード (565K) -
林 伸和, 小林 政教, 畠中 辰哉2006 年 56 巻 2 号 p. 94-99
発行日: 2006年
公開日: 2006/06/16
ジャーナル フリーThis study aims to produce an aluminum alloy with excellent friction characteristics by powder metallurgical (P/M) method. Al-20%Si powder was mixed with SiC fiber of diameter 13 μm, heated to 773 K, and hot-extruded to a rod. Al-20%Si alloy without fiber was also made by the same procedure. From the rod, the friction pin with round top was made, and the friction characteristic against aluminum sheet A1050-H24 was examined. Friction pin load was changed from 9.8N to 92.7N under at speed 1 mm/s. In small pin load at no lubricant, the burning occurred in the alloy with SiC fiber but did not occur in the alloy without fiber. The friction coefficient of the alloy without fiber was smaller than that of the alloy with SiC fiber between 9.8N and 45.6N. When the pin load increased, however, the burning in the alloy with SiC fiber disappeared. Friction coefficient of the alloy with fiber decreased with increasing the pin load, but that of the alloy without fiber kept almost the same value. Finally the friction coefficient of the alloy with the fiber indicated a lower value at 92.7N than that of the alloy without fiber. Thus, we were able to indicate a possibility of producing a new friction material.抄録全体を表示PDF形式でダウンロード (1397K) -
岩村 信吾, 美浦 康宏2006 年 56 巻 2 号 p. 100-104
発行日: 2006年
公開日: 2006/06/16
ジャーナル フリーThe ternary Al3Sc1-XZrX precipitates formed in the Al-0.15mass%Sc-0.16mass%Zr alloy aged at 763 K for up to 106s were analyzed with the STEM-EDS technique, and the nucleation and growth process for the precipitates were discussed. The obtained results show that the precipitates with 23-53 nm in radius were revealed to consist of Al3Sc1-XZrX phase with increasing substitution ratio, X, from the center toward the surface. The binary Al3Sc phase precipitates preferentially in the early stage of aging (103s-104s), and the Al3Sc1-XZrX phases cover the Al3Sc nucleus in the later stage of aging (105s-106s). The composite particle in the ternary Al-0.15Sc-0.16Zr alloy has a smaller growth rate than the binary Al3Sc particle in the binary Al-0.20Sc alloy at 763 K. These results were well understood in terms of slower diffusion of Zr than Sc in the matrix.抄録全体を表示PDF形式でダウンロード (845K) -
松永 格, 松田 謙治, 畑山 東明, 篠崎 賢二, 天沼 成一, 吉田 誠2006 年 56 巻 2 号 p. 105-111
発行日: 2006年
公開日: 2006/06/16
ジャーナル フリーM40J carbon fiber reinforced aluminum-2.4, 4.7 and 10mass% magnesium alloy composite wires were continuously fabricated using ultrasonic infiltration method. The tensile strength of the composites varied from 800 to 1200 MPa caused by change in cross sectional area, volume fraction of fibers and so on. Moreover, their tensile strength decreased with the increase in Mg content in aluminum. In the case of the Al-10mass%Mg matrix composites, Al3Mg2 intermetallic compound was found on the surface of fibers and continuously formed between fibers in the matrix like bridging. The decrease in the strength would be caused by premature fracture and bridging of the intermetallic compound between fibers. As the result, the tensile strength of the CF/Al composites was controlled by cross sectional area and amount and shape of Al3Mg2 intermetallic compound in aluminum matrix.抄録全体を表示PDF形式でダウンロード (1769K) -
半谷 禎彦, 北原 総一郎, 天田 重庚2006 年 56 巻 2 号 p. 112-116
発行日: 2006年
公開日: 2006/06/16
ジャーナル フリーThe porosity in die castings has an influence on their mechanical properties or air leakage efficiency. To reduce the porosity, we examined compression tests of disk shaped ADC12 aluminum alloy die castings at room temperature. Also, finite element analyses are carried out corresponding to the compression tests. The porosity of the die castings decreases when the compression strain of the specimen increases, particularly in the middle area of the specimen where many defects exist. Thus, this type of compression load is significantly efficient in reducing the variation in the quality of die castings. However, it is necessary to investigate the condition of compression strain that prevents the initiation of cracks during the compression loading.抄録全体を表示PDF形式でダウンロード (821K) -
藤野 隆由, 山口 真一2006 年 56 巻 2 号 p. 117-120
発行日: 2006年
公開日: 2006/06/16
ジャーナル フリーAluminum has excellent workability and surface finishing, but it corrodes easily and has low hardness. In this study, a high corrosion resistance oxide film was prepared first by hydrothermal treatment on aluminum in the primary treatment. Subsequently, nano MnO2 particles were immobilized on minute high corrosion resistance oxide film by hydrothermal treatment. Specifically aluminum was maintained for 30 minutes under 483 K (2.0 MPa) conditions in a 0.04 mol/l aluminum nitrate aqueous solution by hydrothermal treatment. Then, MnO2 was immobilized by hydrothermal treatment for 30 minutes under 453-483 K (1.0-2.0 MPa) conditions in a potassium permanganate aqueous solution on the boehmite film. A thick boehmite film (20 μm) was prepared by adding aluminum nitrate formed globules in the primary treatment, and it possessed wide surface area. Nano MnO2 particles (30 nm) were immobilized onto the boehmite film in a potassium permanganate aqueous solution by hydrothermal treatment in the secondary treatment. In this manner a MnO2-boehmite composite film with wide surface area and high oxidation activity was prepared successfully and for the first time.抄録全体を表示PDF形式でダウンロード (684K) -
大崎 修平, 近藤 秀樹, 木下 勝之2006 年 56 巻 2 号 p. 121-127
発行日: 2006年
公開日: 2006/06/16
ジャーナル フリーFor underaged Al-Mg-Si alloys with excess Si, No. 5 (Al-0.7mass%Mg-1.1mass%Si) and No. C5 with 0.2mass%Cr addition, SSRT tests were carried out to reveal the SCC process and relation to hydrogen embrittlement at strain rate 6.9×10-7/s under three environments; (1) dry nitrogen gas, (2) wet air with 90% relative humidity and (3) an acid sodium chloride (ISO) solution. Under env. (2), alloy No. 5 with coarse grains shows a decrease in elongation comparing with that under the inert env. (1), while alloy No. C5 with finer gains exhibits rather an increase. On the ruptured specimen, the small areas of intergranular- and transgranular-facet with a trace of wavy slip exist bounded on the specimen surface, respectively, which are regarded as an evidence of hydrogen-enhanced localized plasticity. Under env. (3), alloy No. 5 shows a high susceptibility to SCC, while alloy No. C5 exhibits a low that improved through Cr addition. On the SCC fracture surface of alloy No. 5, three modes of intergranular facets with crystallographic pits and with fine ledges and transgranular facet with an appearance of quasi-cleavage are presented, which support the existence of a mechanism of plastic deformation localization induced by anodic dissolution. There is a participation of hydrogen embrittlement in the SCC process, still the effect is small.抄録全体を表示PDF形式でダウンロード (1382K)
解説
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山本 悟2006 年 56 巻 2 号 p. 128-135
発行日: 2006年
公開日: 2006/06/16
ジャーナル フリーPDF形式でダウンロード (1644K)
連載講座
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千葉 晃司2006 年 56 巻 2 号 p. 136-141
発行日: 2006/02/28
公開日: 2021/06/30
ジャーナル フリーPDF形式でダウンロード (1300K)
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